Bone and butterfly the leg of lamb. Cut it into two equal pieces, trim off any excess skin or fat, and make a few incisions in the flesh with the point of a sharp knife and place in marinade. Cover with plastic wrap and transfer to the refrigerator overnight.

The next day, cook the lamb in the oven at 400° for the first 15 minutes and then reduce the temperature to 325° for a further 20 to 25 minutes if you like your lamb pink, 10 minutes longer if you like it well done.

You can make tzatziki to accompany the Moroccan marinade. Grate a peeled whole cucumber, add a pinch of salt, and place in a colander to drain for 15 minutes. Then mix in a half cup Greek yogurt, one crushed clove of garlic, and season with sea salt and freshly ground black pepper. Add two tablespoons of chopped mint and mix well.